A typical such door hinge has a first housing and a second housing that can be inserted into respective recesses in the door frame and a narrow edge of the door panel and a link assembly that connects the housings and has a least two links connected to one another pivotably at a vertical hinge pin. The link assembly is rotatable and usually axially or longitudinally movably on the first housing in two separate inserts that are spaced from one another. These inserts are fastened jointly to a connector body extending over the height of the link assembly and the connector body with the inserts carried thereon and the link assembly are all adjustable in the vertical direction relative to the first housing.
The alignment of the vertical axis relates to the conventional installation situation of the door hinge.
Different configurations are known for concealed door hinges. By comparison with door hinges with an exposed hinge knuckle, the advantage is produced that doors can be integrated optimally in planar wall surfaces without being visible when the door is closed. As a result, the advantage is produced that when the door is closed the hinges are protected from environmental influences, damage or tampering. Furthermore, due to the form of the link assembly specially adapted pivoting sequences can be provided, in order also for example to be able to open doors with an offset. Finally, concealed door hinges frequently have an opening angle of 180°.
In order that the door panel can still be adjusted in the door frame even after installation, door hinges frequently have adjusting mechanisms making possible adjustment in three directions. The height of the door panel in the door frame can be adjusted by a height adjustment in the vertical direction. With a lateral adjustment in the horizontal direction parallel to the faces of the door panel, the door panel can be moved laterally with respect to its closed position inside the door frame. Finally, an adjustment of the door panel in the direction its thickness is possible, which is designated as a compression adjustment. This designation derives from the fact that an adjustment in the direction of the thickness as a rule determines the force with which a seal between the door panel and the door frame is compressed.
Various approaches are known for making the height adjustment.
According to U.S. Pat. No. 7,861,378, a height adjustment in the vertical direction can be achieved in that the entire first housing is carried by longitudinal slots on the door frame or on the door panel. However, this then produces the disadvantage that the milled groove must have a certain oversize, and the height adjustment is also difficult.
According to U.S. Pat. Nos. 8,621,717, 8,683,651, 6,829,808 and DE 101 64 979, the first housing is fixed on the door panel or on the door frame, and the inserts are then movable with the link assembly relative to the first housing. In particular, an adjusting mechanism can be provided that exerts force in the vertical direction onto the lower insert, so that the link assembly is raised or lowered with the two inserts in the first housing. However, this then results in the disadvantage that during adjustment the acting forces are transmitted via the link assembly and the mounting thereof to the inserts, and also it is not possible to rule out considerable play.
According to U.S. Pat. No. 8,863,361, US 2010/0115729, DE 10 2009 038 955 and U.S. Pat. No. 8,196,265, starting from the known basic form of a recessed door hinge the inserts are rigidly retained on a main body, and this main body is adjustable in the vertical direction relative to separate end pieces. This then produces the advantage that the main body and inserts form a rigid unit that can withstand vertical loads. However, even with such a multipart structure, considerable play can be produced that, in the event of high loading of the door hinge, can lead to misalignment or wear.
A door hinge with the features described in the introduction is known in the art and marketed by Koblenz SPA under the product designation Kubica® K2400. The inserts that support the link assembly are fastened to a common connector body extending over the height of the link assembly and the connector body with the inserts and the link assembly is adjustable as a unit in the vertical direction relative to the first housing. The stability of the door hinge requires further improvement, especially when carrying a substantial weight.